U.S. patent application number 12/111078 was filed with the patent office on 2009-10-29 for systems and methods for measurement and feedback of channel quality indicator information.
This patent application is currently assigned to Sharp Laboratories of America, Inc.. Invention is credited to Kimihiko Imamura, Huaming Wu, Shugong Xu.
Application Number | 20090268624 12/111078 |
Document ID | / |
Family ID | 41214918 |
Filed Date | 2009-10-29 |
United States Patent
Application |
20090268624 |
Kind Code |
A1 |
Imamura; Kimihiko ; et
al. |
October 29, 2009 |
SYSTEMS AND METHODS FOR MEASUREMENT AND FEEDBACK OF CHANNEL QUALITY
INDICATOR INFORMATION
Abstract
User equipment may receive configuration information indicating
whether the user equipment provides feedback of channel quality
indicator (CQI) information in virtual resource block mode or
physical resource block mode. If the configuration information
indicates that the user equipment provides feedback in virtual
resource block mode, the user equipment may calculate the CQI
information for virtual resource blocks. The user equipment may
feed back the CQI information for the virtual resource blocks to a
Node B.
Inventors: |
Imamura; Kimihiko;
(Vancouver, WA) ; Xu; Shugong; (Vancouver, WA)
; Wu; Huaming; (Vancouver, WA) |
Correspondence
Address: |
AUSTIN RAPP & HARDMAN
170 SOUTH MAIN STREET, SUITE 735
SALT LAKE CITY
UT
84101
US
|
Assignee: |
Sharp Laboratories of America,
Inc.
Camas
WA
|
Family ID: |
41214918 |
Appl. No.: |
12/111078 |
Filed: |
April 28, 2008 |
Current U.S.
Class: |
370/252 |
Current CPC
Class: |
H04W 24/10 20130101;
H04L 41/08 20130101; H04W 48/08 20130101 |
Class at
Publication: |
370/252 |
International
Class: |
G06F 11/00 20060101
G06F011/00 |
Claims
1. A method for measurement and feedback of channel quality
indicator (CQI) information, the method being implemented by user
equipment, the method comprising: receiving configuration
information indicating whether the user equipment provides feedback
of the CQI information in virtual resource block mode or physical
resource block mode; if the configuration information indicates
that the user equipment provides feedback in virtual resource block
mode, calculating the CQI information for virtual resource blocks;
and feeding back the CQI information for the virtual resource
blocks to a Node B.
2. The method of claim 1, wherein calculating the CQI information
for a particular virtual resource block comprises: calculating the
CQI information for multiple physical resource blocks corresponding
to the virtual resource block; and determining the CQI information
for the virtual resource block based on the CQI information that is
calculated for the multiple physical resource blocks.
3. The method of claim 2, wherein determining the CQI information
for the virtual resource block based on the CQI information that is
calculated for the multiple physical resource blocks comprises
averaging CQI values that are calculated for the multiple physical
resource blocks.
4. The method of claim 2, wherein determining the CQI information
for the virtual resource block based on the CQI information that is
calculated for the multiple physical resource blocks comprises
selecting a maximum CQI value from CQI values that are calculated
for the multiple physical resource blocks.
5. The method of claim 2, wherein determining the CQI information
for the virtual resource block based on the CQI information that is
calculated for the multiple physical resource blocks comprises
selecting a minimum CQI value from CQI values that are calculated
for the multiple physical resource blocks.
6. The method of claim 1, wherein the configuration information is
received via Radio Resource Control signaling.
7. The method of claim 1, wherein the configuration information
comprises a virtual resource block flag that is included within
physical uplink control channel (PUCCH) resource allocation.
8. The method of claim 1, wherein the configuration information
comprises a virtual resource block flag that is included within
physical downlink shared channel (PDSCH) resource allocation.
9. The method of claim 1, wherein the configuration information is
received via L1/L2 signaling.
10. The method of claim 1, wherein the configuration information
comprises a virtual resource block flag that is included within
physical downlink control channel (PDCCH) control signaling.
11. User equipment that is configured for measurement and feedback
of channel quality indicator (CQI) information, comprising: a
processor; memory in electronic communication with the processor;
instructions stored in the memory, the instructions being
executable to: receive configuration information indicating whether
the user equipment provides feedback of the CQI information in
virtual resource block mode or physical resource block mode; if the
configuration information indicates that the user equipment
provides feedback in virtual resource block mode, calculate the CQI
information for virtual resource blocks; and feed back the CQI
information for the virtual resource blocks to a Node B.
12. The user equipment of claim 11, wherein calculating the CQI
information for a particular virtual resource block comprises:
calculating the CQI information for multiple physical resource
blocks corresponding to the virtual resource block; and determining
the CQI information for the virtual resource block based on the CQI
information that is calculated for the multiple physical resource
blocks.
13. The user equipment of claim 12, wherein determining the CQI
information for the virtual resource block based on the CQI
information that is calculated for the multiple physical resource
blocks comprises at least one of: averaging CQI values that are
calculated for the multiple physical resource blocks; selecting a
maximum CQI value from the CQI values that are calculated for the
multiple physical resource blocks; and selecting a minimum CQI
value from the CQI values that are calculated for the multiple
physical resource blocks.
14. The user equipment of claim 11, wherein the configuration
information is received via at least one of Radio Resource Control
signaling and L1/L2 signaling.
15. The user equipment of claim 11, wherein the configuration
information comprises a virtual resource block flag, and wherein
the virtual resource block flag is included within at least one of:
physical uplink control channel (PUCCH) resource allocation;
physical downlink shared channel (PDSCH) resource allocation; and
physical downlink control channel (PDCCH) control signaling.
16. A Node B that configures user equipment (UE) to measure and
provide feedback of channel quality indicator (CQI) information,
comprising: a processor; memory in electronic communication with
the processor; instructions stored in the memory, the instructions
being executable to: send configuration information which indicates
whether the UE provides feedback of the CQI information in virtual
resource block mode or physical resource block mode; receive the
CQI information from UEs; and decide a modulation and coding scheme
that is used for data transmission for each UE based at least on
the received CQI information and the configuration information.
17. The Node B of claim 16, wherein the configuration information
is sent via at least one of Radio Resource Control signaling and
L1/L2 signaling.
18. The Node B of claim 16, wherein the configuration information
comprises a virtual resource block flag, and wherein the virtual
resource block flag is included within at least one of: physical
uplink control channel (PUCCH) resource allocation; physical
downlink shared channel (PDSCH) resource allocation; and physical
downlink control channel (PDCCH) control signaling.
19. A computer-readable medium comprising executable instructions
for: receiving configuration information indicating whether user
equipment provides feedback of channel quality indicator (CQI)
information in virtual resource block mode or physical resource
block mode; if the configuration information indicates that the
user equipment provides feedback in virtual resource block mode,
calculating the CQI information for virtual resource blocks; and
feeding back the CQI information for the virtual resource blocks to
a Node B.
20. The computer-readable medium of claim 19, wherein calculating
the CQI information for a particular virtual resource block
comprises: calculating the CQI information for multiple physical
resource blocks corresponding to the virtual resource block; and
determining the CQI information for the virtual resource block
based on the CQI information that is calculated for the multiple
physical resource blocks.
21. The computer-readable medium of claim 20, wherein determining
the CQI information for the virtual resource block based on the CQI
information that is calculated for the multiple physical resource
blocks comprises at least one of: averaging CQI values that are
calculated for the multiple physical resource blocks; selecting a
maximum CQI value from the CQI values that are calculated for the
multiple physical resource blocks; and selecting a minimum CQI
value from the CQI values that are calculated for the multiple
physical resource blocks.
22. The computer-readable medium of claim 19, wherein the
configuration information is received via at least one of Radio
Resource Control signaling and L1/L2 signaling.
23. The computer-readable medium of claim 19, wherein the
configuration information comprises a virtual resource block flag,
and wherein the virtual resource block flag is included within at
least one of: physical uplink control channel (PUCCH) resource
allocation; physical downlink shared channel (PDSCH) resource
allocation; and physical downlink control channel (PDCCH) control
signaling.
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to wireless
communications and wireless communications-related technology. More
specifically, the present disclosure relates to systems and methods
for measurement and feedback of channel quality indicator
information.
BACKGROUND
[0002] Wireless communication devices have become smaller and more
powerful in order to meet consumer needs and to improve portability
and convenience. Consumers have become dependent upon wireless
communication devices such as cellular telephones, personal digital
assistants (PDAs), laptop computers, and the like. Consumers have
come to expect reliable service, expanded areas of coverage, and
increased functionality.
[0003] A wireless communication device may be referred to as user
equipment, a mobile station, a subscriber station, an access
terminal, a remote station, a user terminal, a terminal, a
subscriber unit, etc. The term "user equipment" (UE) will be used
herein.
[0004] A wireless communication system may provide communication
for a number of cells, each of which may be serviced by a Node B. A
Node B may be a fixed station that communicates with UEs. A Node B
may alternatively be referred to as a base station, an access
point, or some other terminology.
[0005] UEs may communicate with one or more Node Bs via
transmissions on the uplink and the downlink. The uplink (or
reverse link) refers to the communication link from the UEs to the
Node B, and the downlink (or forward link) refers to the
communication link from the Node B to the UEs. A wireless
communication system may simultaneously support communication for
multiple UEs.
[0006] Wireless communication systems may be multiple-access
systems capable of supporting communication with multiple users by
sharing the available system resources (e.g., bandwidth and
transmit power). Examples of such multiple-access systems include
code division multiple access (CDMA) systems, time division
multiple access (TDMA) systems, frequency division multiple access
(FDMA) systems, and orthogonal frequency division multiple access
(OFDMA) systems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 illustrates an example showing how virtual resource
blocks (VRBs) may be mapped to physical resource blocks (PRBs);
[0008] FIG. 2 illustrates a block interleaver corresponding to the
VRB-to-PRB mapping scheme shown in FIG. 1;
[0009] FIG. 3 illustrates an example of a format of a downlink
grant;
[0010] FIG. 4 illustrates an example showing how CQI information
may be calculated based on PRBs;
[0011] FIG. 5 illustrates an example showing how CQI information
may be calculated based on VRBs;
[0012] FIG. 6 illustrates an example of a method for measurement
and feedback of channel quality indicator information;
[0013] FIG. 7 illustrates an example of a method for calculating
CQI information for a particular virtual resource block;
[0014] FIG. 8 illustrates various components that may be utilized
to implement the methods shown in FIGS. 6 and 7;
[0015] FIG. 9 shows an example of Radio Resource Control (RRC)
signaling between a Node B and user equipment;
[0016] FIG. 10 shows an example of how to select VRB/PRB CQI
feedback;
[0017] FIG. 11 shows another example of how to select VRB/PRB CQI
feedback;
[0018] FIG. 12 shows another example of how to select VRB/PRB CQI
feedback; and
[0019] FIG. 13 illustrates various components that may be utilized
in a wireless device.
DETAILED DESCRIPTION
[0020] The 3rd Generation Partnership Project, also referred to as
"3GPP," is a collaboration agreement that aims to define globally
applicable Technical Specifications and Technical Reports for 3rd
Generation Systems. 3GPP Long Term Evolution (LTE) is the name
given to a project to improve the Universal Mobile
Telecommunications System (UMTS) mobile phone or device standard to
cope with future requirements. The 3GPP may define specifications
for the next generation mobile networks, systems, and devices. In
one aspect, UMTS has been modified to provide support and
specification for the Evolved Universal Terrestrial Radio Access
(E-UTRA) and Evolved Universal Terrestrial Radio Access Network
(E-UTRAN).
[0021] The examples described herein are relevant to wireless
communication systems that are configured in accordance with 3GPP
LTE. However, these examples should not be interpreted as limiting
the scope of the present disclosure. The systems and methods
described herein may also be applicable in other wireless
communication systems that utilize orthogonal frequency division
multiplexing (OFDM), such as IEEE 802.16m.
[0022] The downlink transmission scheme for a 3GPP LTE system is
based on OFDM. In an OFDM system, the available spectrum is divided
into multiple carriers, called sub-carriers. Each of these
sub-carriers is independently modulated by a low rate data
stream.
[0023] Orthogonal frequency division multiple access (OFDMA) allows
the access of multiple users on the available bandwidth. Each user
may be assigned a specific time-frequency resource. The data
channels may be shared channels; i.e., for each transmission time
interval, a new scheduling decision may be taken regarding which
users are assigned to which time/frequency resources during that
transmission time interval.
[0024] A radio frame may be divided into a certain number of
equally sized slots. A sub-frame may consist of two consecutive
slots.
[0025] Several different channels are defined for a 3GPP LTE
system. For transmission on the downlink, user data is carried on
the physical downlink shared channel (PDSCH). Downlink control
signaling on the physical downlink control channel (PDCCH) is used
to convey the scheduling decisions to individual UEs. The PDCCH is
located in the first OFDM symbols of a subframe.
[0026] Modulation and coding for the shared data channel is not
fixed, but is adapted according to radio link quality. The UEs
regularly report channel quality indicator (CQI) information to the
Node B.
[0027] For transmission on the uplink, user data is carried on the
physical uplink shared channel (PUSCH). The physical uplink control
channel (PUCCH) carries uplink control information, e.g., CQI
reports and ACK/NACK information related to data packets received
in the downlink. The UE uses the PUCCH when it does not have any
data to transmit on the PUSCH. If the UE has data to transmit on
the PUSCH, the UE multiplexes the control information with data on
the PUSCH. In the downlink, acknowledgement/negative
acknowledgement (ACK/NACK) information is sent on a physical hybrid
ARQ indicator channel (PHICH).
[0028] Data is allocated to the UEs in terms of resource blocks.
Resource blocks are used to describe the mapping of certain
physical channels to resource elements. Physical resource blocks
and virtual resource blocks are defined.
[0029] A physical resource block is defined as a certain number of
consecutive OFDM symbols in the time domain and a certain number of
consecutive subcarriers in the frequency domain.
[0030] A virtual resource block is of the same size as a physical
resource block. Two types of virtual resource blocks are defined:
virtual resource blocks of localized type, and virtual resource
blocks of distributed type.
[0031] Virtual resource blocks of localized type are mapped
directly to physical resource blocks such that virtual resource
block n.sub.VRB corresponds to physical resource block
n.sub.PRB=n.sub.VRB.
[0032] Virtual resource blocks of distributed type are mapped to
physical resource blocks such that virtual resource block n.sub.VRB
corresponds to physical resource block
n.sub.PRB=f(n.sub.VRB,n.sub.s), where n.sub.s is the slot number
within a radio frame. The virtual-to-physical resource block
mapping is different in the two slots of a subframe.
[0033] In a 3GPP LTE system, there are two typical schemes to
transmit signals. One scheme is distributed transmission, and
another scheme is localized transmission. In the case of localized
transmission, data allocation in the VRB (virtual resource block)
is the same as in the PRB (physical resource block). However, in
the case of distributed transmission, data is allocated by using
VRB-to-PRB mapping.
[0034] The present disclosure proposes a method of CQI measurement
and feedback based on either VRB or PRB mapping to optimize
feedback information for distributed or localized transmission and
associated switching mechanisms.
[0035] A method for measurement and feedback of channel quality
indicator (CQI) information is disclosed. The method may be
implemented by user equipment. The method may include receiving
configuration information indicating whether the user equipment
provides feedback of the CQI information in virtual resource block
mode or physical resource block mode. If the configuration
information indicates that the user equipment provides feedback in
virtual resource block mode, the method may also include
calculating the CQI information for virtual resource blocks. The
method may also include feeding back the CQI information for the
virtual resource blocks to a Node B.
[0036] Calculating the CQI information for a particular virtual
resource block may include calculating the CQI information for
multiple physical resource blocks corresponding to the virtual
resource block, and determining the CQI information for the virtual
resource block based on the CQI information that is calculated for
the multiple physical resource blocks.
[0037] Determining the CQI information for the virtual resource
block based on the CQI information that is calculated for the
multiple physical resource blocks may include averaging CQI values
that are calculated for the multiple physical resource blocks.
Alternatively, determining the CQI information for the virtual
resource block based on the CQI information that is calculated for
the multiple physical resource blocks may include selecting a
maximum CQI value from CQI values that are calculated for the
multiple physical resource blocks. Alternatively, determining the
CQI information for the virtual resource block based on the CQI
information that is calculated for the multiple physical resource
blocks may include selecting a minimum CQI value from CQI values
that are calculated for the multiple physical resource blocks.
[0038] The configuration information may be received via Radio
Resource Control signaling. The configuration information may
include a virtual resource block flag that is included within
physical uplink control channel (PUCCH) resource allocation.
[0039] The configuration information may include a virtual resource
block flag that is included within physical downlink shared channel
(PDSCH) resource allocation.
[0040] The configuration information may be received via L1/L2
signaling. The configuration information may include a virtual
resource block flag that is included within physical downlink
control channel (PDCCH) control signaling.
[0041] User equipment (UE) that is configured for measurement and
feedback of channel quality indicator (CQI) information is also
disclosed. The UE includes a processor and memory in electronic
communication with the processor. Instructions are stored in the
memory. The instructions may be executable to receive configuration
information indicating whether the user equipment provides feedback
of the CQI information in virtual resource block mode or physical
resource block mode. If the configuration information indicates
that the user equipment provides feedback in virtual resource block
mode, the instructions may also be executable to calculate the CQI
information for virtual resource blocks. The instructions may also
be executable to feed back the CQI information for the virtual
resource blocks to a Node B.
[0042] A Node B (NB) that configures user equipment (UE) to measure
and provide feedback of channel quality indicator (CQI) information
is also disclosed. The NB includes a processor, and memory in
electronic communication with the processor. Instructions are
stored in the memory. The instructions may be executable to send
configuration information which indicates whether the UE provides
feedback of the CQI information in virtual resource block mode or
physical resource block mode. The instructions may also be
executable to receive the CQI information from UEs. The
instructions may also be executable to decide a modulation and
coding scheme that is used for data transmission for each UE based
at least on the received CQI information and the configuration
information.
[0043] A computer-readable medium for facilitating measurement and
feedback of channel quality indicator (CQI) information is also
disclosed. The computer-readable medium includes executable
instructions. The instructions may be executable to receive
configuration information indicating whether user equipment
provides feedback of the CQI information in virtual resource block
mode or physical resource block mode. If the configuration
information indicates that the user equipment provides feedback in
virtual resource block mode, the instructions may also be
executable to calculate the CQI information for virtual resource
blocks. The instructions may also be executable to feed back the
CQI information for the virtual resource blocks to a Node B.
[0044] In accordance with the present disclosure, a UE calculates
CQI feedback information based on either the virtual resource
blocks (VRBs) or the physical resource blocks (PRBs). The NB
selects one scheme for each UE from the above two. The Node B (NB)
configures whether the UE provides feedback in VRB or PRB mode.
This configuring may be done, for example, via RRC (Radio Resource
Control) signaling or L1/L2 signaling (on the PDCCH).
[0045] VRB-to-PRB mapping provides frequency diversity by
distributing the data to the entire system bandwidth. FIG. 1
illustrates an example showing how VRBs 102 may be mapped to PRBs
104. Each VRB 102 has an index 106 associated with it, and each PRB
104 has an index 108 associated with it. The index 106 associated
with a particular VRB 102 will be referred to as the VRB index 106,
and the index 108 associated with a particular PRB 104 will be
referred to as the PRB index 108.
[0046] A horizontal axis 110 is shown adjacent the VRBs 102.
Movement in a left-to-right direction along the horizontal axis 110
corresponds to increasing values of the VRB index 106.
[0047] A horizontal axis 112 is shown adjacent the PRBs 104.
Movement in a left-to-right direction along the horizontal axis 112
corresponds to increasing frequency.
[0048] As shown in FIG. 1, VRB-to-PRB mapping allows data to be
distributed in the frequency domain in order to provide frequency
diversity. 3GPP specified 1 VRB index corresponding to 2 PRB index,
which means Nd is always two in 3GPP LTE.
[0049] FIG. 1 also shows the gap value 114. As shown, slot 1 in PRB
104 and slot 2 in PRB 104 have a shifted structure. The gap value
114 indicates how much we should shift to create slot 2 mapping
from slot 1 mapping.
[0050] The mapping of VRB indices 106 to PRB indices 108 in FIG. 1
is defined by a block interleaver 216 in FIG. 2. The block
interleaver 216 will be specified in 3GPP LTE.
[0051] Nd is two in 3GPP LTE. So, there are 4 columns 218 in the
block interleaver 216 shown in FIG. 2. The number of rows 220 in
the block interleaver 216 shown in FIG. 2 is N.sub.RB/4Nd, where
N.sub.RB is the number of RBs (resource blocks) in the whole system
bandwidth. Therefore, to define the block interleaver 216, only
N.sub.RB information is needed.
[0052] The gap value 114 in FIG. 1 is also defined by N.sub.RB. So
if both the UE and the NB know N.sub.RB, there is no need to use
any signaling between the NB and the UE to communicate the mapping
of VRB indices 106 to PRB indices 108 in FIG. 1.
[0053] FIG. 3 illustrates an example of a format of a downlink
grant 322. This format of a downlink grant 322 includes control
information for the PDSCH, such as RB assignment 324 (i.e., the
number of RB allocation bits), modulation and coding scheme (MCS),
distribution transmission flag 326, etc.
[0054] The distribution transmission flag 326 indicates whether the
mapping of resource blocks 102, 104 will be localized or
distributed. In the case of localized mapping, VRB indices 106 are
mapped directly to PRB indices 108. But in the case of distributed
mapping, VRB indices 106 are mapped to PRB indices 108 as shown in
FIG. 1.
[0055] Referring to FIG. 4, currently in 3GPP LTE systems, CQI
information is calculated based on each physical resource block
404. So if the UE is in distributed transmission mode, the NB needs
all of the CQI information of the physical resource blocks 404
which correspond to each virtual resource block 402. In the example
shown in FIG. 4, the UE feeds back CQI information corresponding to
4 PRB indices 408 in order to provide CQI information which
corresponds to 2 VRB indices 406.
[0056] Referring to FIG. 5, the present disclosure proposes to
calculate CQI values based on each virtual resource block 502
instead of the above scheme and to select one scheme from these
schemes. FIG. 5 shows how to calculate CQI information based on
virtual resource blocks 502.
[0057] In accordance with the present disclosure, the UE may
measure the quality of each physical resource block 504 and
calculate the average 528 of two physical resource blocks 504 which
are included in one virtual resource block 502. The UE may then
feed back only one CQI value for each virtual resource block 502.
Taking the average 528 is just one example. A different function
(e.g., taking the minimum or taking the maximum) may be used
instead of averaging. Another example could be a way which
maximizes the bits carried in the two PRB of this VRB, e.g. new
MCS.
[0058] Thus, in the example shown in FIG. 5, the UE only feeds back
CQI information which corresponds to 2 virtual resource blocks 502,
instead of CQI information which corresponds to 4 physical resource
blocks 504 (as was the case in the example shown in FIG. 4). If we
assume that CQI information for both virtual resource blocks 502
and physical resource blocks 504 will be carried by k bits per
resource block, CQI information which corresponds to 2 virtual
resource blocks 502 needs 2k bits and CQI information which
corresponds to 4 physical resource blocks 104 needs 4k bits.
Therefore, we can reduce the number of feedback bits to half
compared to the approach illustrated in FIG. 4 in the case of
distributed transmission.
[0059] FIG. 6 illustrates an example of a method 600 for
measurement and feedback of channel quality indicator (CQI)
information. The method 600 may be implemented by user equipment
(UE).
[0060] The method 600 may include receiving 602 configuration
information. The configuration information may be received from the
Node B. The configuration information may indicate whether the UE
should provide feedback of CQI information in virtual resource
block mode or physical resource block mode.
[0061] If the configuration information indicates 604 that the UE
should provide feedback of CQI information in physical resource
block mode, then the UE calculates 608 CQI information for physical
resource blocks 104. However, if the configuration information
indicates 604 that the UE should provide feedback of CQI
information in virtual resource block mode, then the UE calculates
606 CQI information for virtual resource blocks 602. The UE then
feeds back 610 the CQI information to the Node B.
[0062] FIG. 7 illustrates an example of a method 700 for
calculating CQI information for a particular virtual resource block
102. The method 700 may include determining 702 which physical
resource blocks 104 correspond to the virtual resource block 102.
The method 700 may also include calculating 704 CQI information for
the physical resource blocks 104 that correspond to the virtual
resource block 102.
[0063] The method 700 may also include determining 706 CQI
information for the virtual resource block 102 based on the CQI
information that is calculated for the corresponding physical
resource blocks 104. For example, the CQI values that are
calculated for the physical resource blocks 104 may be averaged. As
another example, the maximum of the CQI values that are calculated
for the physical resource blocks 104 may be selected. As another
example, the minimum of the CQI values that are calculated for the
physical resource blocks 104 may be selected.
[0064] FIG. 8 illustrates various components that may be utilized
to implement the methods 600, 700 shown in FIGS. 6 and 7.
[0065] User equipment (UE) 832 is shown. The UE 832 may include a
mode selection component 854. The mode selection component 854 may
be configured to determine whether the UE 832 operates in PRB mode
(where CQI information is calculated for physical resource blocks
104) or VRB mode (where CQI information is calculated for virtual
resource blocks 102). This determination may be made based on
configuration information 872. The configuration information 872
may be received from a Node B 830. The Node B 830 may include a UE
configuration component 868, which may be configured to send the
configuration information 872 to the UE 832.
[0066] The UE 832 may also include a PRB-based CQI calculation
component 856. The PRB-based CQI calculation component 856 may be
configured to calculate CQI information for physical resource
blocks (PRBs) 104. The PRB-based CQI calculation component 856 may
be utilized to calculate CQI information if the UE 832 is
configured to operate in PRB mode.
[0067] The UE 832 may also include a VRB-based CQI calculation
component 858. The VRB-based CQI calculation component 858 may be
configured to calculate CQI information for virtual resource blocks
(VRBs) 102. The VRB-based CQI calculation component 858 may be
utilized to calculate CQI information if the UE 832 is configured
to operate in VRB mode.
[0068] In order to calculate CQI information for a particular
virtual resource block 102, the VRB-based CQI calculation component
858 may be configured to determine which physical resource blocks
104 correspond to the virtual resource block 102, calculate CQI
information for the physical resource blocks 104 that correspond to
the virtual resource block 102, and determine CQI information for
the virtual resource block 102 based on the CQI information that is
calculated for the physical resource blocks 104. For example, the
CQI values that are calculated for the physical resource blocks 104
may be averaged. The VRB-based CQI calculation component 858 may
include an averaging component 860 for providing this
functionality. Alternatively, the maximum of the CQI values that
are calculated for the physical resource blocks 104 may be
selected. The VRB-based CQI calculation component 858 may include a
maximum selection component 862 for providing this functionality.
Alternatively, the minimum of the CQI values that are calculated
for the physical resource blocks 104 may be selected. The VRB-based
CQI calculation component 858 may include a minimum selection
component 864 for providing this functionality.
[0069] The UE 832 may also include a CQI feedback component 866,
which may be configured to send CQI information 874 to the Node B
830. The Node B 830 may include a CQI processing component 870,
which may be configured to process the CQI information 874 that is
received from the UE 832.
[0070] FIG. 9 shows an example of Radio Resource Control (RRC)
signaling between the NB 930 and the UE 932. In this example, the
NB 930 sends the PDSCH and PUSCH resource allocation 934 to the UE
932. Then the NB 930 sends the PUCCH resource allocation 936 for
the uplink ACK/NACK to the UE 932. Then the NB 930 sends the PHICH
resource allocation 938 for the downlink ACK/NACK to the UE 932.
Then the NB 930 sends the PUCCH resource allocation 940 for the
uplink CQI to the UE 932. Then data communication 942 starts. Thus,
as shown in this Figure, the NB 930 configures data resources
(PDSCH/PUSCH resource allocation) and control signaling resources
(PUCCH/PHICH resource allocation) before the NB 930 and the UE 932
exchange the data signals.
[0071] FIG. 10 shows an example of how to select the VRB/PRB CQI
feedback as described above. As shown in this Figure, the PUCCH
resource allocation related RRC signaling from the Node B 1030
includes a "VRB flag" 1044. In particular, the VRB flag 1044 is
included in the PUCCH resource allocation 1040 for the uplink CQI.
Based on this VRB flag 1044, the UE 1032 decides which format it
will use, i.e., PRB feedback (FIG. 4) or VRB feedback (FIG. 5).
[0072] FIG. 11 shows another example of how to select the VRB/PRB
CQI feedback as described above. In this Figure, PDSCH resource
allocation 1134 related RRC signaling from the Node B 1130 includes
a "VRB flag" 1144, which is to indicate VRB or PRB for persistent
data transmission. Based on this VRB flag 1144, the UE 1132 decides
which format will be used, i.e., PRB feedback (FIG. 4) or VRB
feedback (FIG. 5).
[0073] The cases shown in FIGS. 9 through 11 were for persistent
scheduling, where configuration information is sent via RRC
signaling, since the NB changes the RB allocation and the MCS
infrequently. FIG. 12 shows an example of how to select the VRB/PRB
CQI feedback in dynamic scheduling, where configuration information
is sent via L1/L2 signaling (i.e., via PDCCH), since the NB changes
the RB allocation and the MCS frequently.
[0074] FIG. 12 illustrates RRC and L1/L2 signaling between the NB
1230 and the UE 1232. The NB 1230 sends PUCCH resource allocation
1240 for the uplink CQI to the UE 1232. Data communication 1242
between the NB 1230 and the UE 1232 starts. The UE 1232 sends CQI
feedback 1248 to the NB 1230 via the PUCCH/PUSCH. The NB 1230 sends
control information 1250 to the UE 1232 via the PDCCH. Data
transmission 1252 from the NB 1230 to the UE 1232 occurs via the
PDSCH.
[0075] As shown in FIG. 12, control signaling on the PDCCH includes
the "VRB flag" 1244, which is to indicate VRB or PRB for dynamic
data transmission. Based on this VRB flag 1244, the UE 1232 decides
which format it will use, i.e. PRB feedback (FIG. 4) or VRB
feedback (FIG. 5).
[0076] The examples described above were relevant to 3GPP LTE.
However, these examples should not be interpreted as limiting the
scope of the present disclosure. The present disclosure is also
applicable in other OFDM communication systems, such as IEEE
802.16m.
[0077] FIG. 13 illustrates various components that may be utilized
in a wireless device 1302. The wireless device 1302 is an example
of a device that may be configured to implement the methods
described herein. The wireless device 1302 may be a base station or
a mobile station.
[0078] The wireless device 1302 may include a processor 1304 which
controls operation of the wireless device 1302. The processor 1304
may also be referred to as a central processing unit (CPU). Memory
1306, which may include both read-only memory (ROM) and random
access memory (RAM), provides instructions and data to the
processor 1304. A portion of the memory 1306 may also include
non-volatile random access memory (NVRAM). The processor 1304
typically performs logical and arithmetic operations based on
program instructions stored within the memory 1306. The
instructions in the memory 1306 may be executable to implement the
methods described herein.
[0079] The wireless device 1302 may also include a housing 1308
that may include a transmitter 1310 and a receiver 1312 to allow
transmission and reception of data between the wireless device 1302
and a remote location. The transmitter 1310 and receiver 1312 may
be combined into a transceiver 1314. An antenna 1316 may be
attached to the housing 1308 and electrically coupled to the
transceiver 1314. The wireless device 1302 may also include (not
shown) multiple transmitters, multiple receivers, multiple
transceivers and/or multiple antenna.
[0080] The wireless device 1302 may also include a signal detector
1318 that may be used to detect and quantify the level of signals
received by the transceiver 1314. The signal detector 1318 may
detect such signals as total energy, pilot energy per pseudonoise
(PN) chips, power spectral density, and other signals. The wireless
device 1302 may also include a digital signal processor (DSP) 1320
for use in processing signals.
[0081] The various components of the wireless device 1302 may be
coupled together by a bus system 1322 which may include a power
bus, a control signal bus, and a status signal bus in addition to a
data bus. However, for the sake of clarity, the various buses are
illustrated in FIG. 13 as the bus system 1322.
[0082] As used herein, the term "determining" encompasses a wide
variety of actions and, therefore, "determining" can include
calculating, computing, processing, deriving, investigating,
looking up (e.g., looking up in a table, a database or another data
structure), ascertaining and the like. Also, "determining" can
include receiving (e.g., receiving information), accessing (e.g.,
accessing data in a memory) and the like. Also, "determining" can
include resolving, selecting, choosing, establishing and the
like.
[0083] The phrase "based on" does not mean "based only on," unless
expressly specified otherwise. In other words, the phrase "based
on" describes both "based only on" and "based at least on."
[0084] The various illustrative logical blocks, modules and
circuits described herein may be implemented or performed with a
general purpose processor, a digital signal processor (DSP), an
application specific integrated circuit (ASIC), a field
programmable gate array signal (FPGA) or other programmable logic
device, discrete gate or transistor logic, discrete hardware
components or any combination thereof designed to perform the
functions described herein. A general purpose processor may be a
microprocessor, but in the alternative, the processor may be any
conventional processor, controller, microcontroller or state
machine. A processor may also be implemented as a combination of
computing devices, e.g., a combination of a DSP and a
microprocessor, a plurality of microprocessors, one or more
microprocessors in conjunction with a DSP core or any other such
configuration.
[0085] The steps of a method or algorithm described herein may be
embodied directly in hardware, in a software module executed by a
processor or in a combination of the two. A software module may
reside in any form of storage medium that is known in the art. Some
examples of storage media that may be used include RAM memory,
flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a
hard disk, a removable disk, a CD-ROM and so forth. A software
module may comprise a single instruction, or many instructions, and
may be distributed over several different code segments, among
different programs and across multiple storage media. An exemplary
storage medium may be coupled to a processor such that the
processor can read information from, and write information to, the
storage medium. In the alternative, the storage medium may be
integral to the processor.
[0086] The methods disclosed herein comprise one or more steps or
actions for achieving the described method. The method steps and/or
actions may be interchanged with one another without departing from
the scope of the claims. In other words, unless a specific order of
steps or actions is required for proper operation of the method
that is being described, the order and/or use of specific steps
and/or actions may be modified without departing from the scope of
the claims.
[0087] The functions described may be implemented in hardware,
software, firmware, or any combination thereof. If implemented in
software, the functions may be stored as one or more instructions
on a computer-readable medium. A computer-readable medium may be
any available medium that can be accessed by a computer. By way of
example, and not limitation, a computer-readable medium may
comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage,
magnetic disk storage or other magnetic storage devices, or any
other medium that can be used to carry or store desired program
code in the form of instructions or data structures and that can be
accessed by a computer. Disk and disc, as used herein, includes
compact disc (CD), laser disc, optical disc, digital versatile disc
(DVD), floppy disk and Blu-ray.RTM. disc where disks usually
reproduce data magnetically, while discs reproduce data optically
with lasers.
[0088] Software or instructions may also be transmitted over a
transmission medium. For example, if the software is transmitted
from a website, server, or other remote source using a coaxial
cable, fiber optic cable, twisted pair, digital subscriber line
(DSL), or wireless technologies such as infrared, radio, and
microwave, then the coaxial cable, fiber optic cable, twisted pair,
DSL, or wireless technologies such as infrared, radio, and
microwave are included in the definition of transmission
medium.
[0089] It is to be understood that the claims are not limited to
the precise configuration and components illustrated above. Various
modifications, changes and variations may be made in the
arrangement, operation and details of the systems, methods, and
apparatus described herein without departing from the scope of the
claims.
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